Such a multispeed transmission can be realized in a planetary construction and it can be provided for example with a hydro-dynamically operating torque converter which is used as a starting element. The sets of the planetary gear in the multispeed transmission can be switched on for example by means of friction or with switching elements such as clutches and brakes.
From DE 10 2005 002 337 A1 is know a generic multispeed transmission in which the method according to the invention can be employed. The multispeed transmission is provided with a total of four planetary gears arranged one after another, which can be connected via input elements and output elements with a driven input shaft and with an output shaft. The four planetary gears can be switched by means of two brakes as well as by means of three clutches to a total of eight forward gear ratios.
In the multispeed transmissions mentioned above, one of the shifting clutches is continuously connected to the higher gear ratios, and in particular to the fourth through the eighth gear ratio, in order to produce a force flow in the transmission. To provide a coasting mode in these higher gear ratios, it is possible to open the clutch which is permanently connected in the higher gears in order to interrupt the force flow in the transmission.
In the coasting mode, it is a common practice to decouple the drive unit from the output, and in particular for example by interrupting the force flow between the input shaft of the transmission and the output shaft of the transmission. In this case, the motor vehicle rolls unimpeded without consuming fuel or with a reduced fuel consumption, as well as without a drag torque on the side of the drive unit, so that the fuel consumption can be reduced. Such a coasting mode is known for example from DE 10 2010 000 857 A1.